Field of the Invention
Embodiments of the invention generally relate to a vacuum processing chamber for etching high aspect ratio feature in semiconductor substrates and the like.
Description of the Related Art
The demand for faster, more powerful integrated circuits (IC) devices has introduced new challenges for IC fabrication technology, including the need to etch high aspect ratio of features such as trenches or vias on a substrate such as a semiconductor wafer. For example, deep trench storage structures used in some dynamic random access memory applications require deep high aspect ratio trenches etched into a semiconductor substrate. Deep silicone trench etching is typically carried out in a reactive ion etching (RIE) process utilizing silicon oxide mask.
One conventional system which has shown robust performance in etching high aspect ratio features is the CENTURA HART™ Etch System, available from Applied Materials, inc. located in Santa Clara, Calif. The HART™ etching system utilizes a MERIE reactor capable of etching trenches having aspect ratios up to 70:1 while maintaining trench depth uniformity of 5 percent from center to edge. However, in order to enable fabrication of integrated circuits having sub-90 nm critical dimensions, circuit designers have demanded improved uniformity trench uniformity at event high aspect ratios. Thus, it would be desirable to improve etching performance to enable the realization of next generation devices.
Therefore, there is a need for an improved apparatus for etching high aspect ratio features.